Villain was a regular TAG, so I figured he wouldn't call anything in a board like this. I could have called the turn, but even though A3, A6 or a runner runner flush was rather improbable, I decided to raise. Then he 3bets me; my intention was to call but I misclicked and folded.

I think the misclick was a fortunate accident, after all... who would 3b the turn in a board like this? What you guys think?

I would go 3 streets for value, if I check back flop then I would not really raise that turn card, because if you raise and he 3-bets you are at very bad situation: he might easily 3-bet bluff and he can expect be ahead all his sets/straights so he would likely also 3-bet them for value.